Stephanie Henderson-Begg’s research while affiliated with University of East London and other places

Ice nucleation has previously been described in only a few lichens from a single location. Here we greatly extend this work and suggest that in lichens ice nucleation is a water harvesting adaption. Fifty-seven lichen samples from a variety of widespread locations were tested for ice nucleation by differential scanning calorimetry (DSC). Samples initiated freezing in the range '5.1° to '20°C and the median freezing temperature was '7.2°C. The vapour pressure difference between ice and water is significant at this temperature, and so ice grows at the expense of water (Bergeron'Findeisen process). Therefore, the ability to form ice at these temperatures provides a useful water-harvesting mechanism for lichens. Ice nucleation appears to be ubiquitous in lichens and is more likely to be associated with the mycobiont and may influence atmospheric processes.

This study compared two programs developed as a learning tool for students to practise basic laboratory procedures. One was a Flash simulation program, the other a Second Life virtual reality program. A cohort of 93 bioscience students participated in the between trial. A control group was used to establish if using either program affected learning or confidence gains. Gains were assessed by collecting pre-demo and post-demo scores. Results showed no difference in gains between the Flash and Second Life conditions but both had significantly higher confidence gains than the control condition. However, the control group had a significantly higher pre-demo score casting some doubt on the reliability of the result. Students scored Flash significantly higher as a learning tool in an evaluation questionnaire. Furthermore, comments from the focus group demonstrated that the majority of students preferred to use Flash finding it easier to use, quicker and with less distractions than Second Life. The University of East London will now focus upon developing the Flash version of the laboratory procedures simulation.

Learning spaces like 3D virtual world environments are recent additions to technological tools believed to have the potential to transform educational processes, especially in flexible / distance education. The immersiveness of the environment affords opportunities for a sense presence lacking from traditional online learning environments. Geographically dispersed students are able to learn in an environment similar to their traditional classrooms without forfeiting the ability to learn at own pace and in their own time. Many educational establishments are however still trying to work out how to use these environments effectively for teaching and learning. Using the environment for assessment adds another level of complication and has been subjected to mixed reviews. Issues relating to matching avatars with ‘real’ students, accessibility and fairness etc., make assessment in Second Life a contentious subject. Many agree however that Second Life offers opportunities for students to enhance their skills in several areas which include scripting, graphics design and 3D object creation. This article explores a case study which used Second Life for summative assessment with a group of 5 students on MSc Applications of Bioinformatics programme.

A pilot study was conducted using a cohort of 18 students, studying for their Bioscience Masters, and carrying out project work throughout the summer. On arrival for a laboratory class the students were asked to complete a baseline confidence log and answer a knowledge quiz. The confidence log and quiz were developed from ideas suggested in Draper et al., (1996). The forms assessed confidence and knowledge in terms of specific, basic laboratory skills which would be able to be practised on the UEL Virtual Lab (http://www.uelconnect.org.uk/hab/UELVirtualLab.html). The confidence log used a visual analogue scale and students were asked to rate how confident they felt in performing a basic laboratory procedures or calculations formulated from each of the sections in the UEL Virtual Lab. The quiz paper had 10 questions testing knowledge of basic laboratory skills. Published (publisher's copy) Peer Reviewed

Development of multiple antibiotic resistance in Streptococcus pneumoniae typically involves either mutation or transformation at several well-separated chromosomal loci. We postulated that this series of genetic events would be more likely to occur in organisms with deficient DNA repair mechanisms. Investigation of 27 antibiotic-resistant or -susceptible clinical isolates of S. pneumoniae revealed a broad range of mutation frequencies, but no isolate was as mutable as a mismatch repair (MMR)-deficient laboratory isolate. No correlation was observed between antibiotic resistance and higher mutation frequency. Examination of a further 180 clinical isolates using a newly developed rapid screen method also failed to identify any isolates with a mutation frequency as high as the MMR-deficient control strain. We argue that there is currently no clear evidence of a distinct population of mutators among clinical pneumococci.

Almost all research on biological ice nucleation has focussed on a limited number of bacteria. Here we characterise several major new sources of biogenic ice nuclei. These include mosses, hornworts, liverworts and cyanobacteria. Ice nucleation in the eukaryotic bryophytes appears to be ubiquitous. The temperature at which these organisms nucleate is that at which the difference in vapour pressure over ice and water is at or close to its maximum. At these temperatures (-8 to -18 degrees C) ice will grow at the expense of supercooled water. These organisms are dependent for their water on occult precipitation - fog, dew and cloudwater which by its nature is not collected in conventional rain gauges. Therefore we suggest that these organism produce ice nuclei as a water harvesting mechanism. Since the same mechanism would also drive the Bergeron-Findeisen process, and as moss is known to become airborne, these nuclei may have a role in the initiation of precipitation. The properties of these ice nuclei are very different from the well characterised bacterial nuclei. We will also present DNA sequence data showing that, although related, the proteins responsible are only very distantly related to the classical bacterial ice nuclei.

The presence of bacteria in clouds may affect their radiation and precipitation properties as some species are able to catalyse the freezing of water at high temperatures (-2C to -10C). Where cloud-borne bacteria originate and the distances they are able to travel in the air remains a mystery. In this study we have attempted to address these issues by comparing metagenomic DNA sequences from air samples with those from other environmental sources. Air samples were collected on 1 July 2009 from a hill top at Thursley Nature Reserve in Surrey, United Kingdom, a rural site, 31 miles from the nearest stretch of coastline, and on 6 July 2009 from the top of a six storey building in Stratford on the East end of London, 38 miles from the nearest coastal area. Samples were collected using the Karcher DS5500 vacuum into a liquid filled collection vessel at an air flow rate of 3.3 m3 min-1 over a 4 hour period. Samples were then concentrated and the bacterial content was investigated by PCR, cloning and sequencing of 16S rRNA genes. During the collection period on 1 July the Royston Weather Station in the South East of England recorded wind speed of 1.9 miles/hour in an Easterly direction, with no cloud cover, relative humidity of 74% and atmospheric pressure of 1021.6 mB. On 6 July wind speed was 9.8 miles/hour in a South Westerly direction, there was light cloud cover, relative humidity was 73.8% and atmospheric pressure was 1002.8 mB. Twenty cloned 16S PCR products from each air sample were sequenced. The species identification of each clone is shown in Table 1. The diversity of bacteria found at both sites was similar, with Stenotrophomona and Pedobacteria species dominating both samples. When the DNA sequences were blasted against the environmental samples database, all sequences were found to display greatest homology to metagenomic DNA from marine sources. This may suggest that the most numerous bacteria in air samples originate in the oceans. Taking account of the wind speed and direction, marine organisms would have been airborne for at least 16 hours in the Thursley sample and for at least 4 hours in the East London sample. The origin and spread of airborne organisms warrants further investigation.

To freeze above −36.5 °C, water requires the presence of an ice nucleus (IN). These can be inert particles or living or dead biological material. As they are the most efficient, inducing freezing at up to −1.8 °C, bacteria are the most widely studied biological IN. Here, we show that there is a huge repository of IN in lichens which comprise a large biomass and are able to become airborne. The lichen IN are similar to those we have detected in urban air, exhibiting heat sensitivity but resistance to lysozyme. This suggests many airborne IN are non-bacterial and that eukaryotic IN may be more important to atmospheric processes than previously thought. Copyright © 2009 Royal Meteorological Society

This study examines students’ reactions to the virtual biosciences laboratory developed in Second Life® (SL) at the University of East London. Final year undergraduates and masters students studying biotechnology took part in a trial of a virtual Polymerase Chain Reaction (PCR) experiment in Second Life and evaluated their experience by anonymous questionnaire. Learning gains were measured at various points during the study using pre- and post-tests, and interaction with demonstrators was monitored and compared during the real life (RL) practical. Both groups showed a significant increase in learning gain over the pre- and post-tests, although no difference in gains between the two groups was detected. However, students who conducted the PCR experiment in SL required significantly less demonstrator assistance during the subsequent RL practical. The SL practical was well received by students, with 92% of participants reporting that they would like to use the system again and many requesting other experiments to be made available in this manner in the future. Published (publisher's copy) Peer Reviewed